UIPickerView 在重新加载时冻结 UI

Question

当 UIPickerView 的索引为 1 或元素数量为 2 时，我的应用程序的 ui 冻结。我真的很困惑，因为它正在运行，然后突然坏了。我做了一些研究，发现它可能与线程有关。有人可以帮我解决 UIPickerView 的问题吗？

// class implements UIPickerViewDelegate, UIPickerViewDataSource, UIGestureRecognizerDelegate

     @IBOutlet weak var planetPickerView: UIView!
     var planetPicker: UIPickerView!

视图已加载：

override func viewDidLoad() {
     super.viewDidLoad()
     //Other code not important 
     configurePlanetPicker()
}

UIPickerView 实现：（skyBalls 是类的数组，其中包含各种数据作为 getter）

 func configurePlanetPicker() {
        planetPicker = UIPickerView(frame: CGRect(x: 0, y: 0, width: planetPickerView.frame.width, height: 70))
        planetPicker.delegate = self
        planetPicker.dataSource = self
        planetPicker.transform = CGAffineTransform(rotationAngle: CGFloat(-90 * (Double.pi/180)))
        planetPicker.frame = CGRect(x: -100, y: 0, width: planetPickerView.frame.width + 200, height: 70)
        planetPicker.showsSelectionIndicator = false
        planetPickerView.backgroundColor = .clear
        let tap = UITapGestureRecognizer(target: self, action: #selector(pickerTapped))
        tap.delegate = self
        planetPicker.addGestureRecognizer(tap)
        planetPickerView.addSubview(planetPicker)
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int { return 1 }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {return skyBalls.count }

    func pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat { return 70 }

    func pickerView(_ pickerView: UIPickerView, widthForComponent component: Int) -> CGFloat { return 70 }

    func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
        let mainView = UIView(frame: CGRect(x: 0, y: 0, width: 70, height: 70))

        let image = UIImageView(frame: CGRect(x: 15, y: 10, width: 40, height: 40))
        image.image = UIImage(named: "\(skyBalls[row].getImage().split(separator: ".")[0])")
        image.contentMode = .scaleAspectFit
        mainView.addSubview(image)

        let titleLbl = UILabel(frame: CGRect(x: 0, y: 50, width: 70, height: 20))
        titleLbl.text = skyBalls[row].getName()
        titleLbl.textColor = .white
        titleLbl.textAlignment = .center
        titleLbl.adjustsFontSizeToFitWidth = true
        mainView.addSubview(titleLbl)

        mainView.transform = CGAffineTransform(rotationAngle: 90 * CGFloat((Double.pi/180)))
        return mainView
    }

    @objc func pickerTapped(tapRecognizer: UITapGestureRecognizer) {
        if tapRecognizer.state == .ended {
            let rowHeight = planetPicker.rowSize(forComponent: 0).height
            let selectedRowFrame = planetPicker.bounds.insetBy(dx: 0, dy: (planetPicker.frame.height - rowHeight) / 2)
            let userTappedOnSelectedRow = selectedRowFrame.contains(tapRecognizer.location(in: planetPicker))
            if userTappedOnSelectedRow {
                let selectedRow = planetPicker.selectedRow(inComponent: 0)
                upgradePlanetName = skyBalls[selectedRow].getName()
                let settings = UIStoryboard(name: "PlanetUpgrade", bundle: .main).instantiateViewController(withIdentifier: "Upgrade") as! UpgradeViewController
                self.present(settings, animated: false)
            }
        }
    }

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }

我确实在按下增加 skyBalls 数组大小的按钮时重新加载 UIPickerView：

planetPicker.reloadAllComponents()

但是如果 planetPicker.reloadAllComponents() 以所有形式从项目中完全删除，问题仍然存在。

我已尝试重述我的 mac、iphone 和 xcode，以及删除派生数据。我清理了 build 文件夹，但似乎无法解决问题。

提前致谢。

Answer 1

当你必须更新你的观点时您必须始终在主线程上调用 .reloadAllComponents() DispatchQueue.main.async 才能解决问题。

DispatchQueue.main.async {
    self.planetPickerView.reloadAllComponents()
}

Answer 2

好的，所以我发现这根本不是 UIpickerView 的错。所以环顾四周后，我尝试了这个：

1) Open "Breakpoint navigator"

2) tap '+' button and choose the "Exception Breakpoint" option

然后我找到了问题的根源是数组索引越界，由于某种原因没有使应用程序崩溃。

UIPickerView 在重新加载时冻结 UI

UIPickerView freezes UI when reloaded

swift

xcode

user-interface

uipickerview

freeze